^ CLEANING SLIDES AND COVER-GLASSES 33 



been washed away. The slides (and the method is a good one for 

 cover-glasses also) may then be placed in absolute alcohol or 

 methylated spirit, and only require drying to be ready for use. 



Another method which I have recently used and found excellent 

 is to boil them in a 5 per cent, solution of lysol ; they may be 

 allowed to remain in this fluid until required, and are then 

 polished with a handkerchief — and it may be pointed out that 

 thorough friction is a sine qua non whatever method of cleaning be 

 adopted. Slides and cover-glasses after use may be soaked in the 

 lysol solution, a pot of which should be kept at hand for the 

 purpose ; they will be sterilized and partially cleaned in a few 

 hours. 



When no properly cleaned slides are at hand, the following 

 method may be adopted, though it is not so good: dip the end 

 of a clean handkerchief in strong spirit (absolute or rectified) and 

 wipe the slide with it, using a considerable amount of friction. 

 Now dry it with the special handkerchief mentioned above, heat 

 it thoroughly in a smokeless flame, and allow to cool completely. 

 Spread the film on the surface which was exposed directly to the 

 flame. 



Cover-glasses are cleaned in the method advised for slides, and 

 should be stored in strong alcohol smelling strongly of ammonia. 

 They are wiped with the special handkerchief immediately before 

 use. 



When cover-glasses are to be used for covering films spread 

 upon slides (as is generally the case if the method recommended 

 in this book is adopted) it is quite sufficient to wipe them care- 

 fully with a clean handkerchief moistened with spirit, and then to 

 dry them. 



After slides or cover-glasses have been cleaned, the utmost care 

 must be taken that they do not come in contact with the skin, or 

 a thin film of grease will be deposited upon them. 



PIPETTES 



Glass pipettes for the collection of pathological fluid for 

 bacteriological examination are very frequently required. They 

 are readily made from a piece of quill glass tubing, and a few 

 should always be kept in stock against emergencies. 



One form consists of a bulb about ^ inch long, each end of 



3 



